The present invention relates to loudspeaker enclosures of the low frequency exponential folded horn type. More specifically, it relates to horn enclosures that are optimized for use on a stage or floor and includes reflex porting in the horn channel.
The current invention relates directly to my previous U.S. Pat. No. 7,520,368 titled “Horizontally Folded Reflex-Ported Bass Horn Enclosure” and can be considered a contribution over my previous invention in that the current invention provides certain advantages by comparatively reducing material and structural complexity by reducing the number of parts, construction operations by reducing the complexity of the remaining parts, and reducing the attendant labor costs, comparatively speaking, without any undue sacrifice of performance. The differences disclosed herein will establish the current invention as being critically distinct in composition and form, with advantages being increased over the cited prior art.
Incorporating the back-wave from a horn driver into a horn channel has been seldom accomplished in the prior art as typically the reflex ports capable of low frequency reinforcement take up too much additional enclosure space, which in the case of a low frequency horn structure is naturally already quite large when seeking an optimal low frequency response. This has led the art in the direction of using a relatively high cutoff for such a bass horn structure to keep it relatively small and necessitating a reflex port tuned to “fill in” the missing low frequencies. This approach still results in a rather large cabinet needed to resonate the typical horn driver below the low frequency cutoff (Fc) of the horn and the porting apparatus displacement which typically reduces the available internal back chamber volume.
Venting reflex ports into a horn channel would eliminate the well-known negative “chuffing” effects associated with ducted ports as well as further preventing excessive bass effects known commonly as “booming”. Additionally, by using the same horn channel, the phase response between frequencies would be better retained and presented to the audience in a cohesive manner. In addition, the dispersion pattern would be controlled by the horn structure.
A horn device using a single low frequency driver which utilizes the back wave from the cone in an additive manner without giving up internal back chamber volume for the port device, and tuned to resonate one or more low frequencies into the horn channel would seem to provide a relatively small footprint and overall size compared to the prior art of the same relative response capabilities.
The current invention is relatively economical to build, increases versatility of placement, operates with high efficiency, and provides advantages heretofore not obtained in the prior art.